Vehicle builders have been using serial communication (multiplexing) between controllers to share information and distribute control for some time. Doing so has greatly reduced the amount of vehicle signal wiring needed to implement the comfort, convenience, and safety features desired in modern consumer vehicles.
Control of the devices in the vehicle to implement desired features may be divided into controllers by function (powertrain, braking, steering, etc.), by location (engine compartment, seat, door, etc.) or in combinations thereof. The controller for each of the functions/zones may share information with other controllers using a shared-access serial bus. The bus usually follows an industry standard such as J1850, CAN, LIN, Flexray, MOST and the like, well known to those of skill in the art. Multiple, independent busses may be used. In that case, one of the controllers may act as a gateway for information between the incompatible busses.
An alternative architecture introduces the idea of dividing the vehicle into geographic regions and locating a single controller for all of the features in that region. This architecture may also include the concept of smart peripherals to reduce the number of interconnections in localized areas of the vehicle. The smart peripherals use simple serial communication busses such as LIN busses to relay information from sensors to the zone controller or to accept actuator commands from the zone controller. The zone controllers may be linked by a serial communication bus structure.
Another alternative architecture incorporates a junction block that can be located in various zones of the vehicle. The junction block provides a mechanical and electrical connection point for power, ground and communication for small devices that are used to interface between input and output devices. The junction block also provides over current protection devices for the small connected devices, and multiple power sources distributed at different levels within the system.
Current bus protocols are not easily scalable and are limited in bandwidth. X-by-wire functionality, multimedia infotainment, navigation and other content intensive applications will put more demands on bandwidth and quality of service (QoS) requiring marked improvements in bandwidth, speed, delay, jitter, fault tolerance, message integrity, guaranteed delivery, availability and survivability.
Therefore, there is needed new architecture, such as switch fabric network architecture, for the automotive environment that provides scalability in both capacity and redundancy, at costs on par with existing bus architecture.